Encounter: Bombay Caecilian, an amphibian epiphany

Its serpentine structure and moist, clammy skin gives the caecilian the appearance of a frog masquerading as a snake. Chances are you’ve seen this intriguing amphibian before but never taken a second look at it!
The head of the Bombay Caecilian, showing the tiny tentacles, mouth and the eyes. Note the ring-like folds on the skin and the whitish secretion of mucus
During our three days at the Agumbe Rainforest Research Station, breakfast conversations with station manager Prashant always yielded something interesting. On the morning of the day we were leaving I asked him casually about his work, and he mentioned in his characteristic unassuming manner that he had been part of the discovery and documentation of some species of Caecilians.
Caecilians! My ears perked up at the word. I hadn’t heard it in a long time and something told me we were very close to an epiphany of sorts.
“Aren’t they legless amphibians?” I asked.
“Yes,” he said laconically.
“And do you get them around here?”
“Yes.”
“Wish we could see them…” I murmured hopefully.
“I could show you one,” he said helpfully. “I have a pet.”
For the rest of the day we were at our best behaviour, grinning and glancing at Prashant hopefully every time we passed him. After lunch he asked us to wait outside a hut that probably served as a storage room for specimens. In its dim murkiness we saw him digging around in a bucket.
The caecilian’s sinuous movements are very like a snake’s

He came out of the hut holding a slender, purplish-black creature that resembled a snake at first glance. But unlike a snake’s skin, which is dry and scaly, this animal’s shiny body surface appeared to secrete mucus that rubbed off in white gobs on Prashant’s hands. He invited me to touch it, and the skin felt soft, cool, slippery and moist under my fingertips. It was like touching a frog masquerading as a snake. This mucus is believed to be mildly toxic to predators, though that doesn’t prevent pigs, snakes and chickens from eating some of the smaller caecilians.

Mucus, secreted by the caecilian’s skin, keeps it moist while its mild toxicity is thought to deter predators
Though their snakelike appearance can be deceptive, caecilians are legless amphibians related to frogs, toads and salamanders. Their serpentine body structure is an adaptation for a burrowing lifestyle. They live among leaf litter and loose soil and can be found under fallen trees and rocks. There are 26 recorded species of caecilians in India, of which 25 are endemic and about 20 of these are found in the Western Ghats. Other caecilians have also been discovered from forests in Manipur and Nagaland in northeast India.
The species we were admiring was the Bombay Caecilian (Ichthyophis bombayensis), which occurs in the Western Ghats. It was nearly a metre long – I had expected caecilians to be much smaller — and the body is annulated (the skin is ringed with folds) as in worms. The two tiny eyes, barely more than dark spots sheathed by skin, are surrounded by pale white rings. This caecilian’s eyesight is perhaps limited to distinguishing between darkness and light. The mouth has rows of small teeth that are adapted for holding and cutting prey, which primarily consists of earthworms, termites and small invertebrates that live in the soil. There are two tentacles close to the mouth and this has perhaps given rise to the myth that these are venomous two-headed snakes — in Kerala they are known as iruthalamoori (literally, two-headed bullock) and killed because they are commonly mistaken for snakes (some resemble the similarly coloured shieldtail snakes).

Snake in the grass? Sadly, many caecilians are easily mistaken for snakes and therefore killed

Caecilians are oviparous, which means they lay eggs. It’s hard to tell males and females apart externally, but males have a concealed copulatory organ, the phallodaeum, which can be inserted like a pseudo-penis into the aperture of the female during copulation. Fertilization takes place inside the female’s body. As with most amphibians, caecilian eggs are strung together in gelatinous threads, like beads in a necklace. The female caecilian protects her clutch of eggs by coiling her body around them. The larvae are aquatic and free-swimming — like tadpoles.

If you happen to visit a plantation of areca, banana or coffee with moist, humus-rich soil and compost pits, look out for caecilians. Just remember that like all amphibians they are highly sensitive to depletion of soil quality and are therefore important environmental indicators.

Prashant treats us to a ampbibian epiphany

As we watched the caecilian with fascination, Prashant put it down on the ground. It moved swiftly through the grass and began looking for a place to hide away from the sunlight. He then put it back in its bucket and announced, “Show is over!”

Thanks, Prashant. We’re all really grateful to you for introducing us to this intriguing amphibian. We have one more reason to keep our eyes glued to the ground in a rainforest. The birds can wait!

References:
A Field Guide to the Caecilians of the Western Ghats, India by Gopalakrishna Bhatta, Department of Zoology, Sri JCBM College, Sringeri, India

Text and additional photos: Beej
Lead photos: Sahastrarashmi
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